1. Field of the Invention
The present invention relates to a portable apparatus, such as a laptop type or portable type computer. More particularly, this invention relates to a structure of securing a printed circuit board to the base unit of the apparatus.
2. Description of the Related Art
Recently, laptop type computers are popular which have a keyboard and a flat panel type display unit mounted to a base unit having a rectangular box shape.
Of portable computers of this type, the one having a leg also serving as a carrying handle provided at the rear portion of its base unit is disclosed in U.S. Pat. No. 4,571,456. This leg is supported on the base unit in a manner movable between a position where the leg is retained in the base unit and a position where it is pulled out from the rear portion of the base unit. When the base unit is placed on a desk with its leg pulled out therefrom, the entire base unit tilts up, setting its keyboard side (front portion) lower than its leg side (rear portion). As a result, the keyboard tilts toward an operator to facilitate the keyboard operation.
According to such a portable computer, the bottom plate of the base unit is bent upward under the keyboard, in order to improve the stability at the time the base unit is tilted.
Published Unexamined Japanese Patent Application No. 62-196900 and Published Unexamined Japanese Utility Model Application No. 63-39985 disclose a portable computer with a base unit having a bent bottom plate. According to this conventional portable computer, the front portion of the bottom plate of the base unit is inclined toward the keyboard side located thereabove. The inclined portion of the bottom plate comes in contact with the top of a desk when the base unit is tilted up using the leg.
The base unit receives inside a printed circuit board having various circuit parts mounted thereon. The printed circuit board is placed on the bottom plate of the base unit and secured at a plurality of sections to this bottom plate by means of screws. When the bottom plate of the base unit is bent, therefore, the printed circuit board is forcibly bent to match the bent shape of the bottom plate by the tightening force of the screws.
The printed circuit board originally has a flat shape. To secure the flat printed circuit board to the bottom plate of the base unit, first the printed circuit board is pressed against the bottom plate of the base unit. Then the screws should be fastened one by one while setting the printed circuit board in consistent with the bent shape of the bottom plate of the base unit.
The printed circuit board, however, has a size matching the entire shape of the bottom plate of the base unit and has a considerably large rigidity with circuit parts mounted on the printed circuit board. At the time the printed circuit board is pressed against the bottom plate of the base unit, strong repelling force acts on the printed circuit board to force it to return to the original shape, thus inconveniencing the work to secure the printed circuit board to the base unit.